Four dream telescopes I want to see built in my lifetime

There are some cool new telescopes being built both for Earth-based observing and in space.

On the ground there are the Giant Magellan Telescope and Thirty Meter Telescope, both of which will see much more deeply and clearly into space thanks to being 5 to 10 times larger than any previous telescopes. And in space there’s the over-budget James Webb Space Telescope which nonetheless should make some awesome discoveries when it launches in 2018 or a bit later.

But that’s not the topic of this post. I want to talk about super telescopes that are grandiose but feasible, and would be capable of making revolutionary discoveries within my lifetime.

1. THE COLOSSUS TELESCOPE

Astronomy magazine did a nice feature on this proposed telescope earlier this year, which seeks to identify alien civilizations on other worlds.

Unlike SETI, which searches for radio waves from other civilizations, the proposed Colossus Telescope would search for heat signals from other worlds, specifically something akin to the urban heat islands created by very large cities on Earth.

A rendering of the proposed telescope. (Colossus Telescope)

Theoretically this is possible, but it requires a very large telescope, on the order of two to three times larger than the Magellan and Thirty Meter telescopes discussed above. Hence the name, colossus.

A telescope of such size would be expensive. And it might find nothing.

But it might answer one of the most important questions humans could ever conceive: Is there intelligent life out there?

Odds of happening by 2050: Fair to good.

2. SUN AS A GRAVITATIONAL LENS

First imagined by Albert Einstein, the concept of gravitational lensing involves the idea that light passing near large objects will be deflected as a result.

A sketch of a lensed system. (Johns/Berkeley)

As it turns out our Sun is a sufficiently large object to deflect light, and for very distant objects this light is focused and magnified. In the case of our Sun, there is a point in space where the light from distant sources is magnified up to 100 million times. Now that would be a fantastic telescope!

The only problem is that the place in space is about 550 astronomical units from the Sun, or 550 times the distance between the Earth and the Sun. Voyager 1, the most distant manmade object from the Sun, is only 126 AU from our star after nearly four decades of travel.

However some mechanisms, such as a solar sail, have been discussed to get an instrument into place to take advantage of this marvelous natural tool.

Odds of happening by 2050: Poor.

3. LUNAR RADIO TELESCOPE

Way back when I was a freshman studying astronomy in college, a professor explained that his dream was to turn the far side of the moon into a giant radio telescope. There it would be free of interference from Earth’s myriad radio signals and, for half of the lunar orbit, the Sun’s as well.

Such a telescope would allow astronomers to peer back further into the early days of the universe than ever before — as early as 15 million years after its formation.

Location and design of the proposed radio telescope. (NRL)

In recent years there has been some theoretical work to devise such a telescope, named the Dark Ages Lunar Interferometer. This would not be a small facility, as it would gather radio signals across as large as a four square-mile area.

Constructing such a large facility would be both expensive and technically demanding, and in the current budget cycle it seems almost unimaginable for NASA to find funds for such an endeavor. But if you’re looking for something for astronauts on the moon to do, this would be something of high scientific importance.

The telescope would have been built upon the success of the Kepler instrument which has identified thousands of planets around other stars, identifying and characterizing Earth-like planets around the 100 closest stars. It could have found worlds that would have been suitable for humans to inhabit.

There are no plans to build a comparable instrument, but it seems the next logical step in the study of exoplanets.